Valve operating means



July 24, 1962 A. c. SAMPIETRO VALVE OPERATING MEANS 4 Sheets-Sheet 1Filed July 22, 1959 r 9 H. 6 3 1 1 9 6 M 3 3 6 9 I 9 4 6 7 u 1 2 u 4 1.A. 5 o I. 8 0 3 1 2 9 ,92 H 8 8 9 I Z 8 I I 1 9 J w .2 6 2 .8 H Z 8 v mm a n I. 2 4L Z m B 2 3 M1 5 1 .1 3 m 6 in u. 1 5 w & Z l 1 W 7 a m u xz 7 4 u I 9 9 M a 9 4. 4 4 (L 4!. 1 O 3 7 M F H 1 .M. M a n nn [17 ye171 UP Zc/Zz'llas C jampv'cira July 24, 1962 A.-C. SAMPIETRO 3,045,657

VALVE OPERATING MEANS Filed July 22, 1959 I 4 Sheets-Sheet 2 I 3IHl/EIJIUF flafiv'l'les C fampvefra July 24, 1962 A. c. SAMPIETRO3,045,657

VALVE OPERATING MEANS Filed July 22, 1959 4 Sheets-Sheet 4 5 I 17 V53 17I 13 r dab/Z65 C Jam $1217 0 @A -HH E.

United States Patent G a Filed July 22, 1959, Ser. No. 828,895 15Claims. (Cl. 12390) The present invention relates to improvements inmechanism for operating valves of an internal combustion engine. Theinvention particularly relates to a mechanism wherein a single cam opensboth the inlet and exhaust valves.

The invention contemplates provision of a valve operating mechanism inan internal combustion engine having overhead inlet and exhaust valvesoperated by rocker arms which are pivotally supported by a mechanismwhich may be provided with means to adjust the lash and to take up wear.Separate rocker arms extend laterally outwardly to engage and operatethe intake and exhaust valves and are provided with followers at theirinner ends which engage a cam means on a single cam shaft for operatingboth of the rocker arms to operate both the inlet and exhaust valves inthe right sequence and at the right time in the cycle.

An object of the invention is to provide an improved valve gear for aninternal combustion engine which is substantially reduced in cost and innumber of parts, eliminating the need for tappets and pushrods andreducing the number of cam shafts required.

Another object of the invention is to provide an improved fulcrumsupport for an engine valve rocker arm which will remove the lash fromthe valve linkage. An object is to provide an improved fulcrum supportto adjust the lash and take up wear in a valve operating linkageutilizing cam means on a single cam shaft, and which will function tohold the valves closed during non-operating periods and during engineoperating periods when the valves are not opened by the cam.

A further object of the invention is to provide an improved connectionbetween a rocker arm and a poppet valve for rotating the valve duringengine operation.

Another object of the invention is to provide an improved valve linkagearrangement for an overhead valve assembly in an internal combustionengine driven by a single cam shaft which is well suited to operationwith or without valve lash adjustment mechanism and is suited tooperation in engines having more than one bank of cylinders.

Other objects and advantages will become more apparent with the teachingof the principles of the inven tion in the disclosure of the preferredembodiments thereof in the specification, claims and drawings in which:

FIGURE 1 is a vertical sectional view taken through a cylinder of aninternal combustion engine provided with a valve operating mechanism inaccordance with the principles of the present invention;

FIGURE 2. has an end elevational view shown in schematic form of a camshaft drive arrangement for an engine having plural banks of cylinders;

FIGURE 3 is an enlarged detailed vertical sectional view takensubstantially along the line IIIIII of FIG- URE l but showing the camshaft in a different rotational position;

FIGURE 4 is a vertical sectional view, similar to FIG- URE 1 showing amodified embodiment of the invention; and

FIGURE 5 is a vertical sectional view similar to FIG- URES l and 4showing another modified embodiment of the invention.

As shown on the drawings:

In FIGURE 1 there is illustrated in a fragmentary 3,045,657 PatentedJuly 24, 1962 ice manner a valve and head type of engine to which anyone of the several forms of the invention can be adapted. The internalcombustion engine illustrated includes a cylinder block 11 and acylinder head 12. The head 12 is provided with an intake passage 14 froma siutable manifold and an exhaust passage 16 leading to a suitablemanifold, wth the manifolds not being shown. The intake of the fuel airmixture into the cylinder 13 is controlled by an intake valve 18 shownto be of the poppet type with a valve stem 19 slidable in a stem guide17 mounted in the head 14. The valve 18 has a head 21 which coacts witha valve seat 22 to open or close the intake passage 14 as the intakevalve 18 is opened and closed.

The exhaust passage 16 is provided with an exhaust valve 24 having avalve stem 26 slidable in a valve guide 23 in the head. The valve 24 hasa valve head 27 which coacts with a valve seat 28 formed on the enginehead in order to control the flow of exhaust gases from the cylinder 13as the poppet type valve 24 is opened and closed.

In the arrangement of FIGURE 1 the valves are opened and are alsopositively closed by rocker arms 29 and 30 respectively for the intakeand exhaust valve 18 and 24. The rocker arms are actuated by a singlecam shaft 31 carrying intake cam means 32 and exhaust cam means 33 and34, as will be described in further detail in connection with FIGURE 3.

The intake rocker arm 29 is connected at its outer end to the valve 18by a rotator connector spool 36 which is held to the top of the valvestem 19 by a nut 37. The upper end of the valve stem is tapered at 38 towedge the spool tightly in place in order that the spool may drive thevalve stem in rotation, as will be described. The exhaust valve 24carries a similar spool 39 at its upper end and the upper end of thevalve stem is tapered with the spool being forced down against the taperby a nut 41 threaded onto the stem 26.

The outer end 29a of the rocker arm 29 is bifurcated or forked with oneside 42 of the fork being shown. The outer end 30a of the rocker arm 30is also forked with a side 43 of the fork being shown. The sides of thefork of the rocker arm 29 have arcuate lower surfaces 46 which engagethe flange 36b of the spool 36, and the sides of the fork of the rockerarm 30 have lower arcuate surfaces 47 which engage the flange 39b of thespool 39. The arcuate surfaces are identical in the two sides of theforks. The sides of the fork of rocker arm 29 have upper arcuatesurfaces 48 which engage flange 36a of spool 36, and the sides of thefork of rocker arm 30 have upper arcuate surfaces 49 which engage fiange39a of spool 39. The surfaces 48 for the two sides of the fork and thesurfaces 49 for the two sides each have .a slight difference in point ofcontact with their flanges 36a and 39a. As illustrated by the contactsurfaces 49, the side of the fork on the near side in FIGURE 1 engagesthe flange 39a at 51 and the surface of the fork on the far side of thespool engages the fiange at 54. When the valve 24 is moved by the rockerarm there is a scrubbing action between the spool and the fork end.While the scrubbing action on the two sides of the valve stem is thesame while the valve being opened, there is a difference in scrubbingaction when the valve is being closed so as to create unidirectionalvalve rotation. This difference in point of contact is utilized on thupper surfaces of the fork end of each of the rocker arms 29 and 30. Itwill be appreciated by those skilled in the art that in some instancesit may be desirable to utilize the difference in point contact for thelower surfaces of the forked outer ends of the rocker arms, or on boththe upper and lower surfaces.

The inner ends of the rocker arm are operated by the single cam meansthat is located between them. The rocker arm 30 carries a pin 55,FIGURES 1 and 3, se-

cured thereto by cross pins 55a and 55b. The pin 55 carries a centralroller 56 that engages the valve opening cam 32, and with additionalrollers 57 and 58 at each side which follow the conjugate shape of thevalve closing cams 34 and 33 respectively. The valve closing cams areconstructed so that they may conveniently be broached and includesupporting disk members 59 and 61 mounted on the shaft 31, connectedthereto by pins 69 and 71, and also include the cam members 62 and 63which are provided with circular recesses on the side to fit over thedisks 59 and 61 and be secured thereto by the pins 69 and 71. Thus theinner end of the rocker arm 30 is positively moved in both directions tooperate the valve. The other rocker arm 29 also carries a pin 72 with avalve closing roller 73 thereon and with other rollers at the end of thepin operated by the earns 33 and 34. Thus the same valve opening cam 32and valve closing cams 33 and 34 operate both rocker arms 29 and 30.

Because in one of the piston top dead center positions the inlet valveis already open while the exhaust valve is still open, the cam shaftmust rotate in one direction given by the crank shaft rotationaldirection and the location of the inlet and exhaust valve operatingrollers with respect to the cam shaft. Also, because of the angularlength of the cam shaft overlap andthe space requirements for theoperating rollers or pads, the valves are set at an angle and the rockerarms extend angularly outwardly and downwardly.

With the usual configuration used for V or opposed engines, the twovalve operating cam shafts for the two banks of cylinders must rotate inopposed directions. This can be achieved such as by using a rollerchain, and as illustrated in FIGURE 2. The engine 74 has a sprocket 76carried on the crank shaft to drive a roller chain 77. The cam shafts 78and 79 carry sprockets 81 and 82 over which the roller chain is threadedso as to drive them in opposite directions as indicated by the arrows.An idler sprocket 83 permits the roller chain to be threaded around thesecond cam shaft sprocket so as to drive it in an opposing directionfrom the first cam shaft sprocket.

The rocker arms are each supported on fulcrum members illustrated in theform of compound valve lash adjusters 84 and 86. The rocker arms 29, 30are formed with bearing portions 87, 88 which have inner bearingsurfaces 89, 91 and outer bearing surfaces 92, 93a, the bearing surfacespreferably being spherical. The rocker arms pivotally oscillate in thevertical plane defined by the rocker arm and valves, as shown inFIGURE 1. Each of the fulcrum supports 84, 86 for the rocker arms 29, 30include an upper fulcrum adjuster and a lower fulcrum adjuster. Theupper fulcrum adjuster includes a piston 93, 94 suitably mounted andsecured on a piston 93, 94 suitably mounted and secured on a pistonsupport 96, 97 which is rigidly mounted on the engine. The pistonsupports are provided with oil gallerys 98, 99 supplied with pressurizedoil from the engine lubrication system. The pistons are provided withpassages 101, 102 to receive oil from the oil gallerys. The pistons areslidably received by cylinder members 103, 104 which are hollow andwhich with the pistons define pressure chambers 106, 107. The cylindermembers have spherical lower ends 108, 109 which are seated in thespherical bearing surfaces 89, 91 of the rocker arm. Ball check valves111, 112 are positioned at the lower end of the passages 101, 102 andprevent the escape of oil from the pressure chambers 106, 107 and keepthe chambers filled during working. A controlled leakdown from thepressure chambers 106, 107 occurs through the clearance between thepistons 93, 94 and cylinder members 103, 104. The unit leakdown isupward and thus air carried into the pressure chambers 106, 107 by theoil will easily purge.

The pistons 93, 94 are mounted in the piston supports 96, 97 andmounting thereby strips 113, 114, are secured to the supports by seriesof set screws 116, 117 or other fastening means.

The lower lash adjuster in each instance is larger than the top one sothat with equal oil pressure there is a residual force in an upwarddirection tending to close the valve. The upper adjuster is thusrequired only to take up the fulcrum reaction when the valve opens. Thelower lash adjusters include a piston 119, 121 with an upwardly facingconcave spherical surface 122, 123. The piston is shown as being made oftwo parts with a hollow interior but this is not material and it can beformed of a single part. The piston is slidable within the cylindricalinterior of a cylinder member 126, 127 and pressure chambers 128, 129are formed within the cylinder member below the piston. The pistons aresupported in a support member- 130 mounted on the engine head 12, andhaving a chamber 131 therein connected to be supplied pressurized oilfrom the engine lubrication system. Oil flows from this pressure chamberor galley 131 into the pressure chambers 128, 129 of the individuallower fulcrum adjusters forcing the pistons 119, 121 upwardly to holdvalves closed and to take up lash and wear in the valve linkage.Leakdown is in an upward direction to easily purge air.

Springs 132, 133 are mounted in the pressure chamber to urge upwardly onthe pistons and hold the linkage snug and to hold the valve closedduring periods of nonoperation of the engine and during cranking andstarting.

The springs are seated on check valve washers 136, 137. Duringoperation, these washers will be forced upwardly off the bottom of thechambers 128, 129 to permit the flow of oil into the chambers but toprevent back flow. For this purpose, the washers are provided withcentral orifices 138, 139 which are out of alignment with ports 141, 142in the base of the cylinder members 126, 127.

In the arrangement of FIGURE 4, the mechanism is simplified and thevalves are closed by springs. Parts similar to the embodiment of FIGURE1 are numbered similarly with a prime mark after the number. Engineblock 11 is provided with a cylinder 13' and has an intake passage 14and an exhaust passage 16. An intake valve 18 and an exhaust valve 24'are mounted in the head 15 of the engine and the valve stems 19' and 26'are slidable in valve guides 17' and 23'. The valves are closed by coilvalve springs 143 and 144 seated on the head 15 and held to the valvestems by spring retaining washers 146 and 147 secured to the stern bycollars or keys 148 and 149.

The valves are operated by rocker arms 151, 152 which are formed andshaped from sheet steel to a deformed boat shape. The rocker arms haveouter ends 153 and 154 which engage the upper ends of the valve stems19' and 26 and have inner ends or pads 156, 157 which engage the valveopening cam 32' mounted on the cam shaft 31'. The valves are again setat an angle with respect to each other and the rocker arms extendangularly downwardly and outwardly and are positioned with respect tothe cam 32' to operate in the proper timed relationship. The rocker arms151, 152 have inner spherical depressed portions, shown at 158 for therocker arm 152 which receive the lower spherical end of adjustablysupported fulcrum pins 159, 161. The pins are supported in an overheadbnacket 162 and have threaded portions 163, 164 threaded into theoverhead bracket and held in an adjusted position by lock nuts 166, 167.The threaded portions 163 and 164 are screwed up and down in the bracketto adjust the rocker arm clearance. Extensions 168, 169 extenddownwardly from the overhead support bracket 162 to register with theinner surfaces of the rocker arm and prevent them from rotating out oftheir Working plane.

FIGURE 5 illustrates another modified form of the invention wherein thevalves are moved only to open position by the single cam means and areclosed by return springs. The rocker arms. are supported on posts orstuds so that no bending is exerted on the stud and the resultant of allforces put on the stud is in tension at all times. Parts whichcorrespond to the arrangement of FIGURE 1 or to the arrangement ofFIGURE 4 are numbered similarly with a double prime marking.

An engine block 11" has a cylinder 13" and a head 15" mounted thereon.The head has an intake passage 14" and an exhaust passage 16". Thepassages are controlled by an intake valve 1 8 and an exhaust valve 24".The stems 19 and 26 of the valves are mounted in valve guides 17", 23".The valves are held closed by valve springs 143, 144" supported on theengine head 15". The valve springs are connected to the upper ends ofthe valve stems and bear upwardly against valve spring retainer washers146", 147" held to the valve stems by locks 148", 149".

The valves are opened by rocker arms 171, 172 and have outer endsurfaces 173, 174 to engage the upper end of the valve stems. The rockerarms have inner ends or pads 176, 177 which engage the cam 32 on the camshaft 31", with the cam pivoting the rocker arms in timed relationshipto open and close the intake and exhaust valves '18", and 24. The rockerarms are formed of a depressed section of sheet steel and at a centrallocation have a spherical depressed bearing portion 178, 179. Openings181, 182 are formed through the center of the spherical depressedportion to accommodate a post or stud 183, 184 which is threaded intothe engine head 15". A fulcrum support 186, 187 has a lower sphericalsurface which seats in the depressed spherical bearing portion 178, 1'79of the rocker arm and is adjustably held on the post by an adjustmentmember 188, 189 threaded to the upper end of the post. The adjustmentmember is locked in the adjusted position by a locking nut 191, 192.

In the operation of each of the embodiments the valves are positivelyopened by a single cam mounted on acentrally located cam shaft. In thearrangement of FIG- URE 1, a cam shaft 31 carries the valve opening cam32 and the valve closing cams 33 and 34 which operate the rocker arms 29and to positively control position of the valves 18 and 24 and both openand close them. The rocker arms are supported on fulcrum members 84 and86 which are compound valve lash adjusters and the lower fulcrumadjuster has a larger piston and cylinder than the upper fulcrumadjuster so as to positively hold the valve closed and both adjusterstake up lash and wear in the valve linkage.

Thus will be seen that I have provided an improved valve operatingmechanism which meets the objectives and advantages hereinbefore setforth. As compared with a conventional valve gear, the presentarrangement eliminates two tappets, two push rods, and one cam, thussubstantially reducing the cost of construction of an internalcombustion engine. Reduction in parts also increases reliability ofoperation and reduces the chance for breakdown and requirements forservice. The invention is also well suited to use with a simplifiedexpensereducing structure utilizing stamped rocker arms as illustratedin the arrangements of FIGURES 4 and 5.

While each of the illustrations show domed combustion chambers and theshape obtains advantages, the arnangement is not currently in largeproduction because of the cost and complication of the valve gear used.The present arrangement permits the use of a simple valve gear for domedheads by eliminating the disadvantage of the high cost factor. Thearrangement however can also be used with a wedge shape or other shapeof combustion chamber.

The invention incorporates the use of a single cam to open both theinlet and exhaust valves in the right sequence and at the right time inthe cycle, and is Well suited to use with an arrangement, such as shownin FIGURE 1, for positively closed valves by cam operation; or withspring closed valves, as shown in FIGURES 4 and 5 Automatic means toadjust the lash and take up wear may be provided or this may be done byhand adjustment arrangements.

The drawings and specification present a detailed dis closure of thepreferred embodiments of the invention, and it is to be understood thatthe invention is not limited to the specific forms disclosed, but coversall modifications, changes and alternative constructions and methodfalling within the scope of the principles taught by the invention.

I claim:

1. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a rocker arm for operating the valve, a connector at one endof the rocker arm for connecting to a valve, means for pivotally drivingthe rocker arm, a fulcrum member on the rocker arm having a downwardlyfacing convex bearing and an upwardly facing concave bearing, a valveclosing unit having a piston member slidably received in a cylindermember, means for mounting one of said members on the engine, anupwardly facing socket on the other of said members receiving saidconvex bearing, a lash takeup unit having a piston member slidablyreceived in a cylinder member, means for mounting one of said take-upmembers on the engine, means for the other of said takeup memberspivotally received by said concave bearing,

and means for connecting each of said units to the oil pressure systemof the engine, so that the fulcrum memer will be held therebetween.

2. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a valve operator to be connected to the valve, a cam followeron said valve operator, a cam shaft to be driven by the engine, havingcam means thereon in engagement with the follower to intermittentlyclose the valve during engine operation, and a fluid operated chamberwith a movable wall connected to said valve operator and urging theoperator in a direction opposite to the direction in which it is movedby said cam means.

3. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a valve operator to be connected to the valve, a cam followeron said valve operator to be driven by a cam shaft driven by the engineto open the valve in timed relationship to engine operation, an oilchamber having a movable wall connected to said valve operator andurging the valve toward closed position, and means for connecting saidoil chamber to the engine oil pressure system.

4. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylin der, the combinationcomprising a rocker arm for operating the valve, a connector at one endof the rocker arm for connecting to a valve, cam follower means at theother end of the rocker arm to be driven by a cam shaft driven by theengine to open the valve in timed relationship to engine operation, afulcrum member for pivotally supporting the rocket arm, and a fulcrumsupport for said fulcrum member biasing the fulcrum in a direction tohold the valve closed and taking up lash in the valve assembly.

5. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a rocker arm for operating the valve, a connector at one endof the rocker arm for connecting to a valve, cam follower means at theother end of the rocker arm to be driven by a cam driven by the engine,a fulcrum member for pivo-tally supporting the rocker arm, and a lashadjuster for said fulcrum member including a first biasing member urgingthe fulcrurn member in a direction to close the valve, and a secndbiasing member urging the fulcrum member in the opposite direction, atleast one of said biasing members including anexpansible fluid chamberwith a member movable in response to fluid pressure therein.

6. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a rocker arm for operating the valve, a connector at one endof the rocker arm for connecting to a valve, cam follower means at theother end of the rocker arm to be driven by a cam driven by the engine,a fulcrum member for pivotally supporting the rocker arm, and a lashadjuster for said fulcrum member including a first biasing means urgingthe fulcrum member in a direction to open the valve having an expansivefluid chamber with a member movable in response to fluid pressuretherein, and a second biasing means urging the fulcrum member in theopposite direction and having an expansible fluid chamber with a membermovable in response to fluid pressure therein and urging the rocker armin a direction to close the valve, said second biasing means beingstronger than said first.

7. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a rocker arm for operating the valve, a connector at one endof the rocker arm for connecting to a valve, cam follower means at theother end of the rocker arm to be driven by a cam shaft driven by theengine to open the valve in timed relationship to engine operation, afulcrum member for pivotally supporting the rocker arm, a fulcrumsupport for said fulcrum member biasing the fulcrum member in adirection to hold the valve closed and taking up lash in the valveassembly including an expansible oil chamber with a member movable inresponse to oil pressure means for connecting the oil chamber to the oilpressure system of the engine, and spring means biasing said fulcrummember in a direction to hold the valve closed operating in the absenceof oil pressure in said oil chamber.

8. In a valve assembly for an internal combustion engine having acylinder with a valve connected to the cylinder, the combinationcomprising a rocker arm for operating the valve, a connector at one endof the rocker arm for connecting to a valve, cam follower means at theother end of the rocker arm to be driven by a cam shaft driven by theengine to open the valve in timed relationship to engine operation, afulcrum member for pivotally supporting the rocker arm, a fulcrumsupport for said fulcrum member biasing the fulcrum member in adirection to hold the valve closed and taking up lash in the valveassembly including an expansible oil chamber with a member movable inresponse to oil pressure, means for connecting the oil chamber to theoil pressure system of the engine, and means defining a leakdown pathfor oil extending upwardly from said chamber for the escape of air.

9. In a valve assembly for an internal combustion engine having acylinder with a reciprocating poppet valve having a valve stem, thecombination comprising a pivotally mounted rocker arm for operating thevalve in reciprocation by driving the stem, means for pivotallysupporting the rocker arm, means for pivoting the rocker arm, firstmeans connected between the valve stem and rocker arm for driving thevalve connected at a location laterally offset from the axis of the stemand a first distance from the pivotal axis of the rocker arm, and secondmeans connected between the valve stem and rocker arm for driving thevalve connected at a location laterally offset from the axis of the stemand a second distance from the pivotal axis of the rocker arm differentthan said first distance so that said valve will be rotated by saidconnecting means.

10. In a valve assembly for an internal combustion engine having acylinder with a poppet valve the combination comprising a pivotal rockerarm to be connected to the valve for opening and closing the valve,first and second driving surfaces attached to the stem of the valvefacing in opposite axial directions and laterally olfset from the axisof the stern, a first driving element on said rocker arm facing saidfirst surface at a location spaced a first distance from the axis of therocker arm, -a second driving element on said rocker arm facing saidfirst surface at a location spaced a second longer distance from theaxis of the rocker arm, and a third driving element on the rocker armfacing said second surface.

11. In a valve assembly for an internal combustion engine having acylinder with an intake valve for controlling the intake into the enginecylinder, and an exhaust valve for controlling the flow of exhaust gasesfrom the cylinder, an intake rocker arm member to be operativelyconnected to the intake valve for operating the valve, an exhaust rockerarm member operative to be connected to the exhaust valve for operatingthe valve, first and second fulcrum means located to support the rockerarm members in a position extending laterally outwardly to connect tothe valves at their outer ends, means at the outer ends of said rockerarm members for connecting to the valves, a cam shaft to be driven bythe engine, and a single valve closing cam surface and a single valveopening cam surface on the cam shaft in direct engagement with the innerends of each of said rocker arm members so that the valves are openedand closed in timed sequence by said cam surfaces.

12. In a valve assembly for an engine having an intake valve and anexhaust valve, an integrally formed one-piece shaped intake rocker armfor operating the intake valve having upturned side walls, an integrallyformed one-piece shaped exhaust rocker arm for operating the exhaustvalve having upturned side walls, each of said rocker arms having adownwardly facing continuous uninterrupted valve operating surface atthe outer end to reciprocably actuate a valve with pivotal movement ofthe arm, having a bearing surface intermediate the ends for pivotallymounting the rocker arm, and having a downwardly extending projection atthe inner end formed by an outwardly extending formation of the materialof the arm being integral with the arm, first and second fulcrum meansfor the rocker arms engaging the bearing surface of each arm andpivotally supporting the arms to operate the valves, and a rotating camhaving an operating cam surface in direct sliding engagement with theouter surface of the projection at the inner ends of both of the armsfor direct transmission of force to said arms.

13. In a valve assembly for an internal combustion engine having acylinder with an intake valve for controlling the intake into the enginecylinder, and an exhaust valve for controlling the flow of exhaust gasesfrom the cylinder, an intake rocker arm member to be operativelyconnected to the intake valve for operating the valve, an exhaust rockerarm member operative to be connected to the exhaust valve for operatingthe valve, first and second fulcrum means for the rocker arm memberspivotally. supporting said rocker arm members to extend outwardly toconnect to the valves at their outer ends, means at the outer ends ofsaid rocker arm members for operatively connecting to the valves, firstand second followers at the inner ends of said rocker arm members, a camshaft to be driven by the engine extending between said rocker armmembers and having a positive action cam thereon with a radiallyoutwardly facing cam surface and a radially inwardly facing cam surface,said inwardly and said outwardly facing surfaces engaged by both of saidfirst and second followers at circumferentially spaced locations so thatboth followers are operated by the same surfaces of said cam for bothpositive opening and positive closing of the valves.

14. A valve actuating device comprising a formed onepiece rocker arm tobe pivotally mounted for operation, a downwardly facing valve operatingsurface at one end of the rocker arm on the arm to reciprocably actuatea valve with pivotal movement of the arm, a bearing surface intermediatethe ends of the arm for pivotally mounting the rocker arm on a support,an outwardly extending downwardly facing convex projection at the otherend of the rocker arm formed by a continuous uninterrupted formation ofmaterial on the arm, and a cam surface in direct sliding engagement withthe outer surface of said projection on [the rocker arm for directtransmission of force to the arm.

15. A valve actuating device comprising an integrally formed rocker armto be pivotally mounted for operation, a downwardly facing valveoperating surface at one end of the rocker arm to reciprocably actuate avalve with pivotal movement of the arm, a bearing surface intermediatethe ends of the arm for pivotally mounting the rocker arm on a support,and an outwardly projected downwardly facing operating surface at theother end of the arm formed by an outwardly extending formation ofmaterial having an uninterrupted surface for engagement by saidoperating surface with an operator to drive the rocker arm in pivotalmovement and for direct transmission of force to the arm.

5 References Cited in the file of this patent UNITED STATES PATENTS1,188,405 Brush June 27, 1916 1,239,933 Miller et al. Sept. 11, 1917 101,633,882 Ballot June 28, 1927 1,699,659 Fagan Jan. 22, 1929 1,866,293Chandler July 5, 1932 2,338,726 Leake Jan. 11, 1944 2,757,653 Links eta1. Aug. 7, 1956 15 2,813,521 Sampietro Nov. 19, 1957 2,871,720 RalstonFeb. 3, 1959 FOREIGN PATENTS 85,857 Austria Oct. 10, 1921 674,180 GreatBritain r June 18, 1952

